Greetings all; I quite some time back, made a gismo that sits across the bed on TLM, left edge in contact with the chucks closed jaws, that had a squared pocket of pcb materiel for the tool to touch and register using a series of probes moves.
one thing I didn't try at the time was a threading zero'er because it would have taken a second, z offset calibrated bit of pcb to sense the single tooth threading tools. My idea would be to use a vertically arranged, double sided pcb to first move with clearance, to the middle of it, move to touch and apply the math to establish that as the imaginary centerline of the bore, using the front face for threads on the OD with that tool. Then write another stanza of that same code to drive it away and right, away from the pcb so as not to mark it, then drive it inward by .001" thou from the previous contact, and then drive it left until it again contacts the right edge of the pcb, using that contact as a Z offset. Seems like that could be the fixed starting point for a g76 OD threading op where one could be assured of getting a finished thread that actually was the desired OD. if you do the math right. I can certainly rebuild it for that function pair. And make one like it but sized for the Sheldon. Do the same with the single toothed boreing bar, but use the back side of the same bit of pcb. And of course its own x offsets to determine when the tip of the tooth was sitting exactly on the centerline of the z axis. Such a zero setting procedure, if Z needed adjustment, then a new Z offset would need to be incremented, or decremented by an integral number times the current pitch of the thread being cut in order to maintain thread timing between the old shorter thread and the new, longer thread. This it seems, would be better than trying to read the face of a digital caliper with all the tooling in the way, cuz thats a major PITA. Its led to mistakes several times, either because the caliper wasn't dead square, or I couldn't see the display well enough. Is it an idea worth pursuing? Thanks all. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
